package com.attilax.ref;
    import java.lang.reflect.Field;  
    import java.lang.reflect.InvocationTargetException;  
    import java.lang.reflect.Method;  
    import java.lang.reflect.Modifier;  
    import java.lang.reflect.ParameterizedType;  
    import java.lang.reflect.Type;  
    import java.util.ArrayList;  
    import java.util.Collection;  
    import java.util.Date;  
    import java.util.List;  
      
    import org.apache.commons.beanutils.ConvertUtils;  
    import org.apache.commons.beanutils.PropertyUtils;  
    import org.apache.commons.beanutils.converters.DateConverter;  
    import org.apache.commons.lang.StringUtils;  
      
    /** 
     * 反射工具类. 
     *  
     */  
    public class ReflectionUtils {  
      
        static {  
            DateConverter dc = new DateConverter();  
            dc.setUseLocaleFormat(true);  
            dc.setPatterns(new String[] { "yyyy-MM-dd", "yyyy-MM-dd HH:mm:ss" });  
            ConvertUtils.register(dc, Date.class);  
        }  
      
        /** 
         * 调用Getter方法. 
         */  
        public static Object invokeGetterMethod(Object target, String propertyName) {  
            String getterMethodName = "get" + StringUtils.capitalise(propertyName);  
            return invokeMethod(target, getterMethodName, new Class[] {}, new Object[] {});  
        }  
      
        /** 
         * 调用Setter方法.使用value的Class来查找Setter方法. 
         */  
        public static void invokeSetterMethod(Object target, String propertyName, Object value) {  
            invokeSetterMethod(target, propertyName, value, null);  
        }  
      
        /** 
         * 调用Setter方法. 
         *  
         * @param propertyType 用于查找Setter方法,为空时使用value的Class替代. 
         */  
        public static void invokeSetterMethod(Object target, String propertyName, Object value, Class<?> propertyType) {  
            Class<?> type = propertyType != null ? propertyType : value.getClass();  
            String setterMethodName = "set" + StringUtils.capitalise(propertyName);  
            invokeMethod(target, setterMethodName, new Class[] { type }, new Object[] { value });  
        }  
      
        /** 
         * 直接读取对象属性值, 无视private/protected修饰符, 不经过getter函数. 
         */  
        public static Object getFieldValue(final Object object, final String fieldName) {  
            Field field = getDeclaredField(object, fieldName);  
      
            if (field == null) {  
                throw new IllegalArgumentException("Could not find field [" + fieldName + "] on target [" + object + "]");  
            }  
      
            makeAccessible(field);  
      
            Object result = null;  
            try {  
                result = field.get(object);  
            } catch (IllegalAccessException e) {  
                e.printStackTrace();  
            }  
            return result;  
        }  
      
        /** 
         * 直接设置对象属性值, 无视private/protected修饰符, 不经过setter函数. 
         */  
        public static void setFieldValue(final Object object, final String fieldName, final Object value) {  
            Field field = getDeclaredField(object, fieldName);  
      
            if (field == null) {  
                throw new IllegalArgumentException("Could not find field [" + fieldName + "] on target [" + object + "]");  
            }  
      
            makeAccessible(field);  
      
            try {  
                field.set(object, value);  
            } catch (IllegalAccessException e) {  
                e.printStackTrace();  
            }  
        }  
      
        /** 
         * 直接调用对象方法, 无视private/protected修饰符. 
         */  
        public static Object invokeMethod(final Object object, final String methodName, final Class<?>[] parameterTypes,  
                final Object[] parameters) {  
            Method method = getDeclaredMethod(object, methodName, parameterTypes);  
            if (method == null) {  
                throw new IllegalArgumentException("Could not find method [" + methodName + "] on target [" + object + "]");  
            }  
            method.setAccessible(true);  
            try {  
                return method.invoke(object, parameters);  
            } catch (Exception e) {  
                throw convertReflectionExceptionToUnchecked(e);  
            }  
        }  
      
        /** 
         * 循环向上转型, 获取对象的DeclaredField. 
         *  
         * 如向上转型到Object仍无法找到, 返回null. 
         */  
        protected static Field getDeclaredField(final Object object, final String fieldName) {  
            if (object == null) {  
                return null;  
            }  
            if (StringUtils.isBlank(fieldName)) {  
                return null;  
            }  
            for (Class<?> superClass = object.getClass(); superClass != Object.class; superClass = superClass  
                    .getSuperclass()) {  
                try {  
                    return superClass.getDeclaredField(fieldName);  
                } catch (NoSuchFieldException e) {//NOSONAR  
                    // Field不在当前类定义,继续向上转型  
                }  
            }  
            return null;  
        }  
      
        /** 
         * 强行设置Field可访问. 
         */  
        protected static void makeAccessible(final Field field) {  
            if (!Modifier.isPublic(field.getModifiers()) || !Modifier.isPublic(field.getDeclaringClass().getModifiers())) {  
                field.setAccessible(true);  
            }  
        }  
      
        /** 
         * 循环向上转型, 获取对象的DeclaredMethod. 
         *  
         * 如向上转型到Object仍无法找到, 返回null. 
         */  
        protected static Method getDeclaredMethod(Object object, String methodName, Class<?>[] parameterTypes) {  
            if (object == null) {  
                return null;  
            }  
            for (Class<?> superClass = object.getClass(); superClass != Object.class; superClass = superClass  
                    .getSuperclass()) {  
                try {  
                    return superClass.getDeclaredMethod(methodName, parameterTypes);  
                } catch (NoSuchMethodException e) {//NOSONAR  
                    // Method不在当前类定义,继续向上转型  
                }  
            }  
            return null;  
        }  
      
        /** 
         * 通过反射, 获得Class定义中声明的父类的泛型参数的类型. 
         * 如无法找到, 返回Object.class. 
         * eg. 
         * public UserDao extends HibernateDao<User> 
         * 
         * @param clazz The class to introspect 
         * @return the first generic declaration, or Object.class if cannot be determined 
         */  
        @SuppressWarnings("unchecked")  
        public static <T> Class<T> getSuperClassGenricType(final Class clazz) {  
            return getSuperClassGenricType(clazz, 0);  
        }  
      
        /** 
         * 通过反射, 获得定义Class时声明的父类的泛型参数的类型. 
         * 如无法找到, 返回Object.class. 
         *  
         * 如public UserDao extends HibernateDao<User,Long> 
         * 
         * @param clazz clazz The class to introspect 
         * @param index the Index of the generic ddeclaration,start from 0. 
         * @return the index generic declaration, or Object.class if cannot be determined 
         */  
        @SuppressWarnings("unchecked")  
        public static Class getSuperClassGenricType(final Class clazz, final int index) {  
            Type genType = clazz.getGenericSuperclass();  
      
            if (!(genType instanceof ParameterizedType)) {  
                return Object.class;  
            }  
      
            Type[] params = ((ParameterizedType) genType).getActualTypeArguments();  
      
            if (index >= params.length || index < 0) {  
                return Object.class;  
            }  
            if (!(params[index] instanceof Class)) {  
                return Object.class;  
            }  
      
            return (Class) params[index];  
        }  
      
        /** 
         * 提取集合中的对象的属性(通过getter函数), 组合成List. 
         *  
         * @param collection 来源集合. 
         * @param propertyName 要提取的属性名. 
         */  
        @SuppressWarnings("unchecked")  
        public static List convertElementPropertyToList(final Collection collection, final String propertyName) {  
            List list = new ArrayList();  
      
            try {  
                for (Object obj : collection) {  
                    list.add(PropertyUtils.getProperty(obj, propertyName));  
                }  
            } catch (Exception e) {  
                throw convertReflectionExceptionToUnchecked(e);  
            }  
      
            return list;  
        }  
      
        /** 
         * 提取集合中的对象的属性(通过getter函数), 组合成由分割符分隔的字符串. 
         *  
         * @param collection 来源集合. 
         * @param propertyName 要提取的属性名. 
         * @param separator 分隔符. 
         */  
        @SuppressWarnings("unchecked")  
        public static String convertElementPropertyToString(final Collection collection, final String propertyName,  
                final String separator) {  
            List list = convertElementPropertyToList(collection, propertyName);  
            return StringUtils.join(list, separator);  
        }  
      
        /** 
         * 转换字符串到相应类型. 
         *  
         * @param value 待转换的字符串 
         * @param toType 转换目标类型 
         */  
        @SuppressWarnings("unchecked")  
        public static <T> T convertStringToObject(String value, Class<T> toType) {  
            try {  
                return (T) ConvertUtils.convert(value, toType);  
            } catch (Exception e) {  
                throw convertReflectionExceptionToUnchecked(e);  
            }  
        }  
      
        /** 
         * 将反射时的checked exception转换为unchecked exception. 
         */  
        public static RuntimeException convertReflectionExceptionToUnchecked(Exception e) {  
            return convertReflectionExceptionToUnchecked(null, e);  
        }  
      
        public static RuntimeException convertReflectionExceptionToUnchecked(String desc, Exception e) {  
            desc = (desc == null) ? "Unexpected Checked Exception." : desc;  
            if (e instanceof IllegalAccessException || e instanceof IllegalArgumentException  
                    || e instanceof NoSuchMethodException) {  
                return new IllegalArgumentException(desc, e);  
            } else if (e instanceof InvocationTargetException) {  
                return new RuntimeException(desc, ((InvocationTargetException) e).getTargetException());  
            } else if (e instanceof RuntimeException) {  
                return (RuntimeException) e;  
            }  
            return new RuntimeException(desc, e);  
        }  
      
        /** 
         * 得到新的对象 
         * @param <T> 
         * @param cls 
         * @return 
         */  
        public static final <T> T getNewInstance(Class<T> cls) {  
            try {  
                return cls.newInstance();  
            } catch (InstantiationException e) {  
                e.printStackTrace();  
            } catch (IllegalAccessException e) {  
                e.printStackTrace();  
            }  
            return null;  
        }  
    }  